The present invention relates generally to the collection of cellular samples and, more particularly, to a collection apparatus for efficient access and collection of cellular samples from a cytology brush device.
The diagnosis and detection of cell or tissue samples are vital in the prevention and treatment of precancerous and cancerous lesions, or other diseases. Cytology slides are usually prepared to screen and diagnose cellular samples taken from, for example, tissue samples, samples from the uterine cervix, sputum, urethral, bronchial brushings and washings, and other body fluids. Tests used for detecting infections by molecular or immunoassay based technologies also depend on these types of samples and sampling devices. The reliability of the sample obtained, however, is a primary issue.
Due to the typically serious nature of the disease that a doctor is attempting to detect, it is critical that the cell or tissue samples are completely and accurately transferred from the retrieving instrument (i.e. cytology brush device) to the testing medium. Inaccurate retrieval of the cell or tissue sample could possibly result in an inaccurate or delayed diagnosis and even the misdiagnosis of a serious medical condition.
One of the most common uses of cytology slides is for screening and diagnosis of a cervical sample. Carcinoma of the cervix is one of the most common malignancies in women, causing nearly 5,000 deaths per year in the United States. Approximately 60% of these cases are associated with absent or deficient screening. Approximately 25% of the screening failures are the result of errors in cervical sampling or smear interpretation. Saway, George F. (M.D.), Grimes, David A. (M.D.), xe2x80x9cNew Technologies in Cervical Screening: A Word Of Cautionxe2x80x9d, Obstetrics and Gynecology, 1999, Vol. 94, pg. 1, which is incorporated herein by reference.
Cervical sampling traditionally involves microscopic assessment of cervical Papanicolaou smears, called Pap smears. This traditional method for cervical sampling requires scraping a woman""s cervix with a sampling device, such as a cytology brush device, and smearing this sample onto a slide for review by a medical lab professional. The specimen is gently spread across a slide to evenly distribute the cell sample. The slide is then fixed, stained, and examined under a light microscope for cellular abnormalities.
It is, however, difficult to always get a representative sample because a large portion of the cell sample is lodged within the bristles of the cytology brush device making it difficult to transfer all of the cells to a slide by merely wiping the bristles against the smooth slide surface. Thus, valuable diagnostic material is potentially lost, increasing the risk of an erroneous diagnosis.
Furthermore, due to the shape of the brush (i.e. spiral shaped), the cells can be transferred to the slide only by wiping, rubbing or rotating the brush against the slide surface. To transfer even a portion of the cells from this type of brush takes excess time and care. Thus, insufficient cell transfer can be very common when this type of brush and cell transfer method is used.
A variety of technologies or clinical strategies, such as liquid-based cytology systems, have been developed to improve Pap testing. For example, the Cytyc, Inc. (Marlborough, M.A.), ThinPrep(copyright) and the TriPath, Inc. (Burlington, N.C.), CytoRich(copyright) Pap test systems are two commercially available, FDA approved fluid-based methods used for the collection and preparation of cervicovaginal samples.
However, in the liquid-based cytology technique, the accuracy of the resulting sample is again dependent on the successful and complete transfer of the cell samples disposed on the bristles of the cytology brush device to the fixative solution within the container. Typically, this transfer is done by placing the bristled end of the cytology brush device within the container holding the solution. The brush is then manually vortexed within the fixative solution in an attempt to dislodge all of the cells from the bristles. However, the vortexing action within the fixative solution alone is often insufficient to dislodge or flush out all of the cells that are contained on or within the bristles. Again, the disadvantage is that all of the cell sample is not transferred to the fixative solution, resulting in the same problems as discussed above.
A separate technical issue that is problematic when applying cytology brush devices to automated robotic systems is that the shaft of the brush device can interfere with the pipette tips of an automated pipettor. This can actually cause errors in sampling for assays utilizing automation, such as, for example, the Hybrid Capture(copyright) molecular based tests for HPV chlamydia and gonorrhea, by Digene Corporation (Gaithersburg, Md.).
The present invention provides an apparatus that overcomes these problems. A collection apparatus according to one embodiment of the present invention comprises a collection container. The collection container includes an open end and a closed end. A first interior portion of the container at the open end defines a central axis. A second interior portion of the container at the closed end is capable of holding the bristle end of a brush device having a body of bristles on a shaft so that the shaft is angled with respect to the central axis of the first interior portion of the container.
In alternate embodiments, a device including a restricting member is used with a standard collection apparatus to angle the shaft of the brush device from the central axis defined by the first interior portion of the collection apparatus. This device can also be used with the first embodiment described above.